Production of benzines, benzenes, and other hydrocarbons from coal tars and oils



Patented Apr. 11, 1933 UNITED STATES ROBERT EDWIN GOLDSBROUGH, OF SLOUGH, ENGLAND PRODUCTION OF BENZINES,

BENZENES, AND OTHER HYDBOOABBONS FROM COALTABS im oms Application fled March 2l, 1932, Serial No. 600.363, and 'in Great -Britain October 2l, 1930.

The present invention forms in part a continuation of my copending application Serial No. 513,789 iled February 5, 1931, but diers therefrom mainly in that the temperatures 5 used in the present application are given below 700 and 500 C. respectively for the rst and last reaction zones in the heating chamber, whereas in the copending applicationthe corresponding temperature lies above said temperature. The two applications accordingly complement each other.

This invention relates to the conversion of bituminous or ycarbonaceous materials or products, derived therefrom, such as mineral oils, coal oils, tars and roducts derived from any of these, into use ul products including motor spirit, kerosene, like products, lubricating oils, fuel oils, pitch and gases.

In British Patent Specification No. 266,765

there has been described a process of generating 'gas from liquid hydrocarbons by injecting the oil together with steam into a retort in which the mixture expands and is subjected to a gasifying temperature, the gassification bein@` promoted by a device which produces turbulence and pressure changes. The retort and the said device are constructed of a chromium-nickel alloy in which the iickel is usually the predominant constituent.

In British Specification No. 320,619 it has beenshown that in a process of this kind in which the metal surfaces in contact with the heated mixture of steam and oil vapours are coated with a catalyst comprising silica, so-

dium silicate, alumina and zinc oxide, a mixture of liquid hydrocarbons and water is produced by cooling the products, these hydrocarbons comprising light fractions suitable as fuel in internal combustion engines, oils similar to kerosene, a lubricating oil and substances resembling pitch.

`A`ccording to the present invention the metal surfaces, or the greater part thereof,

with which the heated mixture is in contact in the retort are made of nickel-chromium alloy containing small-proportions of silicon, zinc, aluminium and iron, for example an alloy of the following composition:

Percent Nickel 50 Chromium 30 Silicon 1 Zinc 2 Iron v 4 Aluminium 3 The presence of other metals such as molybdenum or titanium or both in proportions up to about 7 per cent. increases the catalytic efficiency of the alloy.

The use of alloys of the kind described in the preceding paragraphs makes it unnecessary to line the retort or other heating chamber with a catalyst ofthe kind described in said British Patent No. 320,619.

In the accompanying drawing is shown diagrammatically and partly in section a retort suitable for carrying out my process.

1 is the entry for superheated steam, 2 is the entry for tar, 3 is the mixing chamber, 9 is a gas burner for heating, 5 is a brickwork, 11 is insulation, 6, 6 are condensers, 8, 8 are outlets from condenser to refinery, 7 is the gas outlet to gas holder.

The steam and raw material are injected at 1 and 2 respectively into a mixing chamber 3 at a pressure above two atmospheres and preferably about three to four atmos heres. The mixing chamber described in ritish Patent No. 226,676 is found to give the best results.

The mixture of vapours and steam having expanded in the mixing chamber passes into the heating chamber or retort consisting preferably of an expansion chamber 10 anda series of retort chambers 4 connected by narrow passages 12.

This may conveniently have the form described and shown in British Patent No. 266,765.

It is impossible to prescribe the best tem- 9 'as it passes from the entrance to the exit of the retort; for example, the chambers 4 of the retort near the exit may be protected from directly applied heat by brickwork 5 and insulatin covering 11 so that it is heated only by conuction, from 350 C. to below 500 C. It is of advantage to remove sulphur from Any known v any raw material containing it.

method of doing this may be adopted;. for

instance the raw material may be e vaporized and passed over iron oxide or the like before it is injected into the mixing chamber `3, or the liquid raw material may be heated with iron oxide, or finally, the iron oxide or like desulphurizing agent may-be injected into the v erating in this manner,

retort together with the mixture.

It has. been found that injection of iron oxide containing titanium oxide about 5% .(a mixture known to -be a good desulp'hurizing agent) has beneficial results upon the process which are not entirely due to desulphurization; hence the injection of such a mixture is regarded as a feature of this invention. 1 'Y It is found that iinelypowdered material blown'into the retort passes through the retort and may separated'from'the elasticI fluid by` means of a dust catcher placed before the condenser;.after appropriate cleansing and drying, if necessary, 1t may be reinjected into the retort with additional advantage since its good effect is enhancedby repeated use after a time, of course, this improvement due to repeated use disappears and. theK eiiiciency of the material falls whereuponl it must be purified, or exchanged for fresh material.

The process may be conducted in an atmosphare of gas which vis preferably the gas ormed in the proces'sand remaining after removal of the c'ondensable hydrocarbons by means of'suitable scrubbing devices; by opthe yield of liquid hydrocarbons may be increased.

' bons with a small amount o The following is an example of the' process conducted in the foregoing apparatus l 100 English gallons of a primary tar, consisting of a mixture of alifphatic hydrocararomatic hydrocarbons and about 40 per cent. of tar acids and other accessoryJ constituents such as bases and the like, are injected, after havlng been preheated to about 200 C., into the retort or retorts 4 by way of a mixing chamber 3 into which su erheated steam is simultaneously injected t rough pipe 1. For 100 English gallons of primary tar, 150 lbs. of steam may y'be used. The temperature of the v.the loss of about '10 retort 4 is approximately below 7 00 C. in the entrance and middle portions and approximately below 500 C. in the exit 4portion of the retort.

The vapour mixture leaving the retort 4 together with the steam is cooled in a suit able fractional separating apparatus to a temperature at which the steam and oil va- Ours of the light fraction separate from the higher oil fraction. The steam is condensed together with the vapours of the light fraction in a suitable condensing apparatus 6,

whereas the heavy fraction which, for example may boil above 230 remains in the fractional separatin apparatus. This latter fraction may be use again and re-circulated for the purpose of producing .a further quantity of light oil.

By operating in the mannr above de'- scribed, itis possible to obtain from 100 English gallons of primary tar, of a light fraction which, after refining, is suitable as a'first class motor spirit and about 50 gallons of heavy fraction which is either wholly or partly suitable for lretreatment; per cent. is accounted for by the formation of permanent gas during the process.

If it is desired to operate in an atmosphere o'f gas, such as the permanent gas produced in the process, the gas may be caused to circulate through the whole plant by means of a pump working under the required pressure the gases entering the mixin chambers of the retorts through separate mlets.

I claim:

1. Ina process for the production of benzines, benzenes and other hydrocarbons from coal-tars and oils, the steps of injecting the I primary material together with steam into a heating zone, the temperature of which is from 450 C. to below 700 C. and being provided with metal surfaces made of about 90% nickel-.chromium alloy containing delinite small proportions of silicon, zinc, aluminium and iron, vaporizing the oil and allowing the reaction material to expand, subjecting the expanded material to turbulence and pressure changes while gradually reducing the temperature of the reaction mixture.

2. AIn a process for the production of benzines, benzenes and other hydrocarbons from coal-tars and oils, the steps of injecting the primary material together with steam into a heating zone, the entering portion of which has a temperature of from 450 to below 700 C., while the exit portion thereof has a temperature of from 350 to below 500 C. and being provided with metal surfaces made of an alloy containing approximately nickel, 30% chromium, 1% silicon, 2% zinc, 3% aluminium, 4% iron, and containing also smaller -definite proportions of zinc oxide,v iron and molybdenum, vaporizing the material, allowing the reaction material to expand by the action of said steam, subjecting the reaction material to turbulence and pressure changes and injectin iron oxide into the heating zone, thereby esulphurizing the material. v

ROBERT EDWIN GOLDSBROUGH. 

